In 802.11 standards for WLANs, the MAC sublayer provides flow control and multiplexing for the transmission medium. Specifically, when sending data to another device on the network, the MAC protocol controls when data is sent, and whether a waiting period is necessary to avoid congestion and collisions from other transmissions that attempt to compete for the same transmission medium. Existing 802.11 standards define a half-duplex medium access for downlink and uplink transmissions. For example, for an access point that communicates with multiple client stations in a WLAN, downlink transmission and uplink transmission are not permitted to happen simultaneously under the current 802.11 standards, because noise cancellation is difficult when downlink transmission and uplink transmission occupies the same channel. Data transmission throughput in the WLAN is thus conventionally limited as downlink and uplink transmission have to take turns to occur.